if __name__=='__main__':
    t = int(input());
    if(t>=30):
        print("Yes");
    else:
        print("No"); if __name__=='__main__':
    t = int(input());
    if(t>=30):
        print("Yes");
    else:
        print("No"); __name__=='__main__' __name__ '__main__' t = int(input()) t int(input()) int input() input if(t>=30):
        print("Yes");
    else:
        print("No"); t>=30 t 30 print("Yes") print "Yes" print("No") print "No" t = int(input()) int(input()) t
if __name__=='__main__':
    t = int(input());
    if(t>=30):
        print("Yes");
    else:
        print("No");